Whilst Bondholder Bombardier is expected to start building Crossrail trains this year, it is also now one of five pre-qualified manufacturers of which have been invited to bid for a new contract worth up to £2.5bn to supply trains for the London Underground.

The winning bidder will design and build trains for the Piccadilly, Bakerloo, Central and Waterloo and City lines by the early 2020s.

Other manufacturers invited to bid include French manufacturer Alstom, Spanish firm CAF, Japanese company Hitachi and Germany's Siemens, however, Hitachi is the only competitor with a UK manufacturing site and is based in the north-east.

Bombardier has also recently completed the delivery of 191 Sub Surface Line trains for London Underground and is the only firm to both design and build trains in the UK.

The new fleet will feature air-conditioned, walk-through carriages capable of offering faster, more frequent and more reliable journeys on the deep-level lines. It will also increase capacity and comfort across the service while maximising accessibility and safety through widened doors.

Nick Brown, Managing Director of London Underground, visited Bombardier's factory before Christmas to help the firm celebrate the completion of the SSL contract. He said: "This invitation to train manufacturers to submit bids for the design and build of the New Tube for London is a significant step forward."